Citation: Yu, L.; Sun, L.; Zhang, Q.;
Zhou, Y.; Zhang, J.; Yang, B.; Xu, B.;
Xu, Q. Nanomaterials-Based
Ion-Imprinted Electrochemical
Sensors for Heavy Metal Ions
Detection: A Review. Biosensors 2022,
12, 1096. https://doi.org/10.3390/
bios12121096
Received: 16 October 2022
Accepted: 25 November 2022
Published: 30 November 2022
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Review
Nanomaterials-Based Ion-Imprinted Electrochemical Sensors
for Heavy Metal Ions Detection: A Review
Liangyun Yu
1
, Liangju Sun
1
, Qi Zhang
2
, Yawen Zhou
1
, Jingjing Zhang
1
, Bairen Yang
2
, Baocai Xu
1,
*
and Qin Xu
3,
*
1
School of Light Industry, Beijing Technology and Business University, No. 11 Fucheng Road, Haidian District,
Beijing 100048, China
2
School of Environmental Science and Engineering, Yancheng Institute of Technology, Yancheng 224051, China
3
College of Chemistry and Engineering, Yangzhou University, Yangzhou 225002, China
* Correspondence: xubac@163.com (B.X.); xuqin@yzu.edu.cn (Q.X.); Tel.: +86-514-8797-5257 (Q.X.)
Abstract:
Heavy metal ions (HMIs) pose a serious threat to the environment and human body
because they are toxic and non-biodegradable and widely exist in environmental ecosystems. It
is necessary to develop a rapid, sensitive and convenient method for HMIs detection to provide
a strong guarantee for ecology and human health. Ion-imprinted electrochemical sensors (IIECSs)
based on nanomaterials have been regarded as an excellent technology because of the good selectivity,
the advantages of fast detection speed, low cost, and portability. Electrode surfaces modified with
nanomaterials can obtain excellent nano-effects, such as size effect, macroscopic quantum tunneling
effect and surface effect, which greatly improve its surface area and conductivity, so as to improve the
detection sensitivity and reduce the detection limit of the sensor. Hence, the present review focused
on the fundamentals and the synthetic strategies of ion-imprinted polymers (IIPs) and IIECSs for
HMIs detection, as well as the applications of various nanomaterials as modifiers and sensitizers in
the construction of HMIIECSs and the influence on the sensing performance of the fabricated sensors.
Finally, the potential challenges and outlook on the future development of the HMIIECSs technology
were also highlighted. By means of the points presented in this review, we hope to provide some
help in further developing the preparation methods of high-performance HMIIECSs and expanding
their potential applications.
Keywords:
electrochemical sensors; heavy metal ions; molecular imprinting; ion imprinting;
nanomaterials
1. Introduction
Rapid industrial development and urbanization have brought about worldwide en-
vironmental pollution, including the almost ubiquitous contamination of heavy metal
ions (HMIs), which are non-biodegradable and carry the risk of entering the human body
through the food chain and poses a significant threat to human health when released
into open areas [
1
,
2
]. The hazard extent of HMIs is closely related to their type, form,
exposure time and dose, so their maximum allowable concentration in the environment
is also different. Drinking water quality standards recommended by the World Health
Organization (WHO), the European Union or the Environmental Protection Agency usually
set maximum pollutant limits between the pm and ppb regimes [3]. Common toxic HMIs
include Hg
2+
, Cd
2+
, Pb
2+
, Cu
2+
, Co
2+
, Cr
3+
, Mn
2+
, and so on. For example, Hg
2+
can cause
damage to kidneys, nervous system and heart system [
4
]. Pb
2+
ingestion in the body can
cause serious harm to the kidney, learning disabilities, decreased intelligence quotient (IQ),
growth retardation and anemia [
5
]. Therefore, we need to develop inexpensive, simple,
and sensitive methods for HMIs detection.
Currently, there are many kinds of conventional methods for detecting HMIs includ-
ing surface-enhanced Raman spectroscopy (SERS), atomic absorption spectrometry (AAS),
Biosensors 2022, 12, 1096. https://doi.org/10.3390/bios12121096 https://www.mdpi.com/journal/biosensors
